This invention relates to .[.stringed apparatus such as.]. stringed rackets .[.and stringed instruments.]. and has particular relationship to the strings forming a part of such .[.apparatus.]. .Iadd.rackets.Iaddend.. .[.The expression stringed apparatus as used in this application means stringed rackets and stringed instruments and other devices to which this invention is applicable. To a large extent this.]. .Iadd.This .Iaddend.application is confined to stringed rackets .[.both in the interest of concreteness and also.]. because the remarkable results which gave rise to this invention have been experienced with rackets. .[.Since the string according to this invention has properties which are advantageous in stringed musical instruments as well as stringed rackets, musical instruments as well as rackets are within the scope of this invention..].
In accordance with the teachings of the prior art, string for stringed rackets are made of animal gut, polymer materials such as polyamide which is sold under the name NYLON, or metals such as steel. Gut is considered to be superior for stringed rackets from the standpoint of the advantage which its use gives to the player. The principal advantage of gut is that it operates with less internal damping than other materials, and the ball rebounds harder and with less loss of energy on impact. Essentially damping is a measure of resilience; when the damping is low, the resilience is high and when the damping is high, the resilience is low. Gut has high resilience. However, gut is high in cost, variable in quality, has only modest strength, has low durability, and is unable to withstand for any length of time high moisture or humid environments. The above disadvantages have limited the use of gut to players who are willing to sacrifice high cost and relatively high probability of failure for better playing characteristics. Polyamides have good durability and good resistance to water or dampness. However, they lack the low damping of gut.
Steel has found limited use because it transfers the numerous impacts of the ball to the frame substantially undamped and is damaging to the frame particularly if it is made of materials other than steel. Steel is also damaging to tennis balls resulting in excessive wear and low life.
.[.A wide variety of materials have been used for strings of musical instruments such as gut, steel, polymers such as polyamides, aluminum, composites such as steel--or aluminum-wound gut or polyamide. The exact material selected depends on the instrument and tonal qualities desired for any particular string. Normally, to achieve lower notes, the density of the strings is increased, for example, steel-wound gut or polyamide is used; and the tension on the string is reduced..].
It is an object of this invention to overcome the above disadvantages of the prior art and to provide string of polyamide having low internal damping for stringed .[.apparatus.]. .Iadd.rackets.Iaddend.. It is another object of this invention to provide improved stringed .[.apparatus.]. .Iadd.rackets .Iaddend.of which polyamide string having low internal damping shall form a part.